The Data-Over-Cable Service Interface Specification (DOCSIS) was established by cable television network operators to facilitate transporting data traffic, primarily Internet traffic, over existing community antenna television (CATV) networks. In addition to transporting data traffic, as well as television content signals over a CATV network, multiple services operators (MSO) also use their CATV network infrastructure for carrying voice, video on demand (VoD) and video conferencing traffic signals, among other types.
In transporting downstream multimedia content, as well as data, upstream messages are typically sent to request the content and to set up a service flow to deliver the content. In addition to downstream multimedia content, such as video, voice traffic also uses message signaling to set up service flows for the upstream and downstream directions.
These signals are typically sent over a fiber network to a location, sometimes referred to as a node, near an end user, and from the node to a broadband user device via a coaxial cable. Such an arrangement is known in the art as a hybrid fiber coax network (HFC).
Typically, when a device is initially connected to the network, the device goes through an initialization process. The initialization process can include scanning the channels to identify downstream channels driven by a headend. Once a downstream channel is identified, the device performs ranging for each upstream channel that it has been configured for and registration processes to join the HFC network. During the course of normal operation each CPE device performs station maintenance upon periodic request from the headend.
Like reference numbers and designations in the various drawings indicate like elements.